The needle member of the present disclosure is a needle member for partitioning a hollow portion, and an opening portion connected to the hollow portion is formed on the side wall of the tube, and a side wall reinforcing portion is formed at a position opposed to the opening and the hollow portion.本開示の針部材は、中空部を区画する針部材であって、管状の側壁には、前記中空部に繋がる開口部が形成されていると共に、前記開口部と前記中空部を挟んで対向する位置に側壁補強部が形成されている。